My Little Monster is a Japanese romance manga written and illustrated by Robico. The central interaction in My Little Monster is between Shizuku Mizutani, a girl who has no hobbies other than studying and her future goals, and Haru Yoshida, a boy who doesn't frequently attend school but sits next to Shizuku in class. Shizuku and Haru begin their friendship when Shizuku is assigned to bring class printouts to Haru's home. Haru welcomes Shizuku as a friend right away. Shizuku is known for being emotionless and chilly, earning the nickname "dry ice." However, she is moved by Haru's naivety and lack of experience with interpersonal interactions when she first meets him. Haru is a nice and caring person, yet he is viewed as a vicious and uncontrollable monster.
1 - Shizuku Mizutani
Shizuku, a high school student, spends all of her time to her studies in order to achieve a future career with a salary of 10 million yen a year. She is considered cold by many for her no-nonsense and blunt attitude and has no friends, but after encountering Haru, she starts expressing more of her emotions and stands up to situations that seem wrong, like when Haru has been used by his alleged friends for money. She starts to feel attracted to Haru despite being annoyed by him and his antics, some of which involve romantic gestures. Although she is happy to be ranked first in her class, Haru, who she once believed to be her intellectual opponent, has changed her perception of what it means to be at the top. Asako Natsume, a student who calls her "Mitty," becomes her first female friend. There have been times when she has let her hair down, though Haru likes the pigtails because he wouldn't be able to find her. She generally prefers wool underwear and clothing that she purchases from sales at retail stores. Shizuku frequently wonders why she finds Haru so charming and attractive during the course of the story.
2 - Haru Yoshida
As a result of being suspended from school for fighting with classmates and continuing to skip classes even after the suspension was lifted, Haru has a reputation for causing problems. Shizuku is the first student to ever do something for him, and he quickly views her as his first true buddy. He engages in numerous shenanigans to be with her, including following her around the school and luring her away from her regular routine. Shizuku is very often surprised when he says that he likes her and might perhaps be in love with her. He is impulsive and free-spirited, frequently hurling insults at others. He is very intelligent academically; to Shizuku's chagrin, he frequently receives the highest exam scores at the school despite not participating in the entrance ceremony and entering high school as the top-ranked student. He also studied the majority of the high school curriculum while skipping most of middle school.
3 - Kenji Yamaguchi
Haru's acquaintance, nicknamed "Yamaken," He was used to hounding Haru for money until Shizuku intervened. He attends a similar cram college as Shizuku, and offers her a useful recommendation on her relationship with Haru. However, he's discomposed that he's progressively drawn to Shizuku and is unwittingly competitive against Haru for her affections. He eventually confesses to Shizuku but is turned down, with Haru and Shizuku before long declaring they're one or two. although Shizuku and Yamaken remain friends. Besides his constant denial that he includes a romantic interest in Shizuku, Yamaken is the subject of continual gags about getting a poor sense of direction and concurrently fleeing on sight from Yuzan as a result of being crushed by him whenever he tries to bully Haru.
4 - Asako Natsume
Asako is Shizuku and Haru's class fellow. Before meeting Shizuku and Haru, she didn't have any friends, aside from some folks from an internet community. She first asks Shizuku to assist her study for a make-up communication test, and then she will attend a real-life meeting with the community. But, the meeting seems to be a disappointment as only the fellows wish to speak with her. She treasures her friendly relationship with "Mitty" and gets depressed whenever Shizuku turns down her interactions with her. She develops a crush on Mitchan as a result of the way he usually comforts her. She feels safe around Haru because he has Shizuku and around Sasayan because he does not fawn over her just like the other boys. Once Mitchan turns down her initial confession, Asako vows to stay, making an attempt to win his heart, till Mitchan turns her down permanently. She later spends more time talking with Sasayan, but she is moved by his candid observations of her behavior and his later mention that he has grown to love her as well.
5 - Sohei Sasahara
Shizuku and Haru's classmates could be popular boys within the baseball team who go by the nickname "Sasayan." He cares about Haru and doesn't need a repeat of what happened in the Gymnasium whenever Haru stopped coming back to high school. He will be particularly blunt once it involves his friends, like giving Asako a truthful, however harsh recommendation regarding falling enamored with Mitchan, and letting Haru's eyes regarding Shizuku's true feelings. He later confesses to Asako that he likes her. He had been curious about Asako since their 1st year in high school, as he needed to apprehend her.
6 - Yuzan Yoshida
Haru's older brother, whom Haru appears to dislike and tries to avoid, At first, he tells Shizuku that he has returned to take Haru home upon their father's request, but once seeing that Haru attends college thanks to Shizuku, he agrees to let him keep him. Though he's popular with the ladies, he gets a little nervous when they make advances on him. When Haru and Yamaken see him in the area, they usually flee. Yuzan and Haru's mother had left the family once they were young, and later, she abandoned her youngsters. Yuzan and Haru were forced back to their father's family once Yuzan was around seven years old. In contrast to Haru, he is set to adapt to the Yoshida way of life. Throughout the series, he tries to move in with Shizuku and provides his recommendations regarding relationships.